Oil Burner Pump
The heart of the oil delivery system. The fuel unit draws oil from the tank, filters it, and delivers it to the nozzle at high pressure for perfect atomization.
Function & Operation
An Oil Burner Pump (often called a Fuel Unit) is a positive displacement gear pump designed to supply fuel oil to the burner nozzle at a stable, high pressure (typically 100-300 PSI).
It performs three critical functions:
- Suction: Lifting oil from the storage tank (up to 3-4 meters vertical lift).
- Filtration: Removing debris via an internal strainer mesh.
- Regulation: Maintaining constant pressure to the nozzle and returning excess oil to the tank or suction side.
Anatomy of a Fuel Unit
Gear Set
Internal gears create suction and pressure. Driven by the burner motor shaft.
Pressure Regulator
A spring-loaded piston/diaphragm that controls the output pressure. Adjustable via a screw.
Solenoid Valve
Electrical cut-off valve (often built-in) that stops oil flow instantly when the burner shuts down.
Troubleshooting Guide
Pressure fluctuation
Often caused by air leaks in the suction line or a clogged filter/strainer. Check vacuum reading.
No Oil Delivery
Pump may not be primed (air lock), coupling may be broken, or motor is not turning.
High Noise
High vacuum (restriction in line), worn gears, or misalignment with motor shaft.
Industry Leaders
- SuntecAS, AN, AL, J, E series (France/USA)
- DanfossBFP 21, BFP 41, RSA series
- WebsterM series, heavy duty
- DeltaVU series
- HP TechnikIndustrial heavy oil pumps
Related Components
One-pipe vs. Two-pipe
One-pipe: Suction only. Used when tank is above burner (gravity feed). Requires bypass plug removal.
Two-pipe: Suction & Return. Used when tank is below burner (lift). Requires bypass plug insertion.